Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Total Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Equity [Abstract]
Net income (loss)	$ (11,219)	$ 25,178
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	21,790	28,791
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	383	219
Total comprehensive income	10,954	54,188
Less: Comprehensive loss attributable to noncontrolling interests	(180)	(23)
Comprehensive income attributable to Belden	11,134	54,211
Foreign currency translation, tax income (loss)	1,000	400
Adjustments to pension and postretirement liability, tax	$ 100	$ 100